Tag: M.W:300-400

The reaction rate of a catalyzed reaction is faster than the reaction rate of the uncatalyzed reaction at the same temperature. Recommanded Product: (4S,4S)-2,2-(Propane-2,2-diyl)bis(4-phenyl-4,5-dihydrooxazole), 131457-46-0, Name is (4S,4S)-2,2-(Propane-2,2-diyl)bis(4-phenyl-4,5-dihydrooxazole), SMILES is CC(C1=N[C@@H](C2=CC=CC=C2)CO1)(C3=N[C@@H](C4=CC=CC=C4)CO3)C, in an article , author is Walaijai, Khanittha, once mentioned of 131457-46-0.

Electrocatalytic Proton Reduction by a Cobalt(III) Hydride Complex with Phosphinopyridine PN Ligands

Cobalt complexes with 2-(diisopropylphosphinomethyl)-pyridine (PN) ligands have been synthesized with the aim of demonstrating electrocatalytic proton reduction to dihydrogen with a well-defined hydride complex of an Earth-abundant metal. Reactions of simple cobalt precursors with 2-(diisopropylphosphino-methyl)pyridine (PN) yield [Co-II(PN)(2)-(MeCN)][BF4](2) 1, [Co-III(PN)(2)(H)(MeCN)][PF6](2) 2, and [Co-III(PN)(2)-(H)(Cl)][PF6] 3. Complexes 1 and 3 have been characterized crystallo-graphically. Unusually for a bidentate PN ligand, all three exhibit geometries with mutually trans phosphorus and nitrogen ligands. Complex 1 exhibits a distorted square-pyramidal geometry with an axial MeCN ligand in a low-spin electronic state. In complexes 2 and 3, the PN ligands lie in a plane leaving the hydride trans to MeCN or chloride, respectively. The redox behavior of the three complexes has been studied by cyclic voltammetry at variable scan rates and by spectroelectrochemistry. A catalytic wave is observed in the presence of trifluoroacetic acid (TFA) at an applied potential close to the Co(II/I) couple of 1. Bulk electrolysis of 1, 2, or 3 at a potential of ca. -1.4 V vs E(Fc(+)/ Fc) in the presence of TFA yields H-2 with Faradaic yields close to 100%. A catalytic mechanism is proposed in which the pyridine moiety of a PN ligand acts as a pendant proton donor following opening of the chelate ring. Additional mechanisms may also operate, especially in the presence of high acid concentration where speciation changes.

But sometimes, even after several years of basic chemistry education, it is not easy to form a clear picture on how they govern reactivity! 131457-46-0, you can contact me at any time and look forward to more communication. Recommanded Product: (4S,4S)-2,2-(Propane-2,2-diyl)bis(4-phenyl-4,5-dihydrooxazole).

Reference:
Metal catalyst and ligand design,
,Ligand Template Strategies for Catalyst Encapsulation – NCBI

One of the major reasons for studying chemical kinetics is to use measurements of the macroscopic properties of a system, such as the rate of change in the concentration of reactants or products with time. 1119-97-7, Name is MitMAB, formurla is C17H38BrN. In a document, author is Han, Binghao, introducing its new discovery. HPLC of Formula: C17H38BrN.

Development of Group 4 Metal Complexes Bearing Fused-Ring Amido-Trihydroquinoline Ligands with Improved High-Temperature Catalytic Performance toward Olefin (Co)polymerization

The development of homogeneous metal catalysts with high activity and high thermal stability is vital for the synthesis of polyolefin elastomers (POEs) in solution-phase olefin polymerization processes. In this contribution, the stoichiometric reactions of 8-(2,6-(R-1)(2)-4-R-2-anilide)-5,6,7-trihydroquinoline (1-3; 1, R-1 = Pr-i, R-2 = H; 2, R-1 = Me, R-2 = H; 3, R-1 = Me, R-2 = Me) with MMe4 (M = Hf, Zr) afforded metal complexes 1-HfMe3, 2-HfMe3, 3-HfMe3, and 1-ZrMe3 in high yields. Treatment of ligand 1 with Ti(NMe2)(4) resulted in the formation of 1-Ti(NMe2)(3), which reacted with SiMe2Cl2 to form 1-TiCl3. 1-TiMe3 was obtained by alkylation of 1-TiCl3 with MeMgBr. All metal complexes were characterized by H-1 and C-13 NMR spectroscopy, and the molecular structures of complexes 1-HfMe3, 2-HfMe3, 1-ZrMe3, and 1-TiMe3 were determined by single-crystal X-ray diffraction, revealing an approximate trigonal-bipyramidal geometry around the metal center in all of the structures. The complexes showed extremely high activity toward ethylene polymerization (up to 13860 kg of PE (mol of M)(-1) h(-1)) and ethylene/1-octene copolymerization (up to 49000 kg of PE (mol of M)(-1) h(-1)) at elevated temperatures (up to 140 degrees C). The catalytic properties were highly dependent on the appropriate matching of the metal and cocatalyst. In the presence of [Ph3C][B(C6F5)(4)], the activity of metal complexes with the same ligand was in the order Hf > Zr > Ti; with B(C6F5)(3) as the cocatalyst, this order followed Zr > Ti > Hf; using MAO as the cocatalyst, the Ti complex was highly active, while the Hf and Zr complexes were inactive. The Hf and Zr complexes showed both high-molecular-weight capability and high 1-octene incorporation ability. Therefore, high-molecular-weight polyethylene homopolymers and ethylene/1-octene elastomers were successfully prepared, and the 1-octene incorporations of copolymers could be readily tuned from 1.3 to 43.5 mol % depending on different catalysts and polymerization conditions.

If you are hungry for even more, make sure to check my other article about 1119-97-7, HPLC of Formula: C17H38BrN.

Reference:
Metal catalyst and ligand design,
,Ligand Template Strategies for Catalyst Encapsulation – NCBI

Reference of 112-02-7, The transformation of simple hydrocarbons into more complex and valuable products via catalytic C¨CH bond functionalisation has revolutionised modern synthetic chemistry. 112-02-7, Name is N,N,N-Trimethylhexadecan-1-aminium chloride, SMILES is CCCCCCCCCCCCCCCC[N+](C)(C)C.[Cl-], belongs to catalyst-ligand compound. In a article, author is Feng, Jian-Rui, introduce new discover of the category.

Theoretical insight into the role of nitrogen in the formic acid decomposition over Pt-13/N-GNS

Catalytic decomposition of formic acid is regarded as one of the most promising hydrogen source conversion technologies. Nitrogen doped carbon supported metal catalyst emerges in recent years and delivers excellent performance in formic acid hydrogenation. However, there is not a well-recognized explanation about the real role of the nitrogen dopant in carbon support. In this work, density functional theory-based calculations were used to individually study the ligand effect and catalytic effect from the nitrogen dopant. Ligand effect mainly tunes the electronic properties of metal active center by shifting d-band center far away from Fermi level. The result unravels that C-H scission path is more favorable compared with O-H scission path. Catalytic effect is originated from the lower electrostatic potential of nitrogen active site compared with platinum, making N site an efficient capturer for hydrogen atom. Though activation energy for cleaving O-H bond is higher than C-H bond, nitrogen site can efficiently cleave the O-H bond. Microkinetic simulations are performed to obtain the best nitrogen doping concentration in the carbon support. It implies that the optimal nitrogen concentration is a function of temperature, according to the optimized curve. This work will improve the understanding of mechanism of formic acid decomposition and provide new method in modifying metal/carbon support catalysts.

Reference of 112-02-7, Each elementary reaction can be described in terms of its molecularity, the number of molecules that collide in that step. The slowest step in a reaction mechanism is the rate-determining step.you can also check out more blogs about 112-02-7.

Reference:
Metal catalyst and ligand design,
,Ligand Template Strategies for Catalyst Encapsulation – NCBI

In an article, author is Bialek, Marzena, once mentioned the application of 206996-60-3, Name is Cerium(III) acetate xhydrate, molecular formula is C6H11CeO7, molecular weight is 335.2633, MDL number is MFCD00150533, category is catalyst-ligand. Now introduce a scientific discovery about this category, Safety of Cerium(III) acetate xhydrate.

Ring opening polymerization of epsilon-caprolactone initiated by titanium and vanadium complexes of ONO-type schiff base ligand

A phenoxy-imine proligand with the additional OH donor group, 4,6-tBu(2)-2-(2-CH2(OH)-C6H4N = CH)C6H3OH (LH2), was synthesized and used to prepare group 4 and 5 complexes by reacting with Ti(OiPr)(4) (LTi) and VO(OiPr)(3) (LV). All new compounds were characterized by the FTIR, H-1 and C-13 NMR spectroscopy and LTi by the single-crystal X-ray diffraction analysis. The complexes were used as catalysts in the ring opening polymerization of epsilon-caprolactone. The influence of monomer/transition metal molar ratio, reaction time, polymerization temperature as well as complex type was investigated in detail. The complexes showed high (LTi) and moderate (LV) activity in epsilon-caprolactone polymerization and the resultant polycaprolactones exhibited M-n and M-w/M-n values ranging from 4.0 center dot 10(3) to 18.7 center dot 10(3) g/mol and from 1.4 to 2.5, respectively.

Do you like my blog? If you like, you can also browse other articles about this kind. Thanks for taking the time to read the blog about 206996-60-3, Safety of Cerium(III) acetate xhydrate.

Reference:
Metal catalyst and ligand design,
,Ligand Template Strategies for Catalyst Encapsulation – NCBI

Reference of 139-07-1, As an important bridge between the micro and macro material world, chemistry is one of the main methods and means for humans to understand and transform the material world. 139-07-1, Name is N-Benzyl-N,N-dimethyldodecan-1-aminium chloride, SMILES is C[N+](C)(CCCCCCCCCCCC)CC1=CC=CC=C1.[Cl-], belongs to catalyst-ligand compound. In a article, author is Takaya, Jun, introduce new discover of the category.

Catalysis using transition metal complexes featuring main group metal and metalloid compounds as supporting ligands

Recent development in catalytic application of transition metal complexes having an M-E bond (E = main group metal or metalloid element), which is stabilized by a multidentate ligand, is summarized. Main group metal and metalloid supporting ligands furnish unusual electronic and steric environments and molecular functions to transition metals, which are not easily available with standard organic supporting ligands such as phosphines and amines. These characteristics often realize remarkable catalytic activity, unique product selectivity, and new molecular transformations. This perspective demonstrates the promising utility of main group metal and metalloid compounds as a new class of supporting ligands for transition metal catalysts in synthetic chemistry.

Reference of 139-07-1, The reactant in an enzyme-catalyzed reaction is called a substrate. Enzyme inhibitors cause a decrease in the reaction rate of an enzyme-catalyzed reaction.I hope my blog about 139-07-1 is helpful to your research.

Reference:
Metal catalyst and ligand design,
,Ligand Template Strategies for Catalyst Encapsulation – NCBI

Application of 139-07-1, Enzymes are biological catalysts that produce large increases in reaction rates and tend to be specific for certain reactants and products. 139-07-1, Name is N-Benzyl-N,N-dimethyldodecan-1-aminium chloride, SMILES is C[N+](C)(CCCCCCCCCCCC)CC1=CC=CC=C1.[Cl-], belongs to catalyst-ligand compound. In a article, author is Li, Ming-Xuan, introduce new discover of the category.

Reversible Mechanochemistry Enabled Autonomous Sustaining of Robustness of Polymers-An Example of Next Generation Self-healing Strategy

Even under low external force, a few macromolecules of a polymer have to be much more highly stressed and fractured first due to the inherent heterogeneous microstructure. When the materials keep on working under loading, as is often the case, the minor damages would add up, endangering the safety of use. Here we show an innovative solution based on mechanochemically initiated reversible cascading variation of metal-ligand complexations. Upon loading, crosslinking density of the proof-of-concept metallopolymer networks autonomously increases, and recovers after unloading. Meanwhile, the stress-induced tiny fracture precursors are blocked to grow and then restored. The entire processes reversibly proceed free of manual intervention and catalyst. The proposed molecular-level internal equilibrium prevention mechanisms fundamentally enhance durability of polymers in service.

Application of 139-07-1, Because enzymes can increase reaction rates by enormous factors and tend to be very specific, typically producing only a single product in quantitative yield, they are the focus of active research.you can also check out more blogs about 139-07-1.

Reference:
Metal catalyst and ligand design,
,Ligand Template Strategies for Catalyst Encapsulation – NCBI

Chemo-enzymatic cascade processes are invaluable due to their ability to rapidly construct high-value products from available feedstock chemicals in a one-pot relay manner. In an article, author is Derrick, Jeffrey S., once mentioned the application of 139-07-1, Name is N-Benzyl-N,N-dimethyldodecan-1-aminium chloride, molecular formula is C21H38ClN, molecular weight is 339.9861, MDL number is MFCD00137276, category is catalyst-ligand. Now introduce a scientific discovery about this category, Recommanded Product: 139-07-1.

Metal-Ligand Cooperativity via Exchange Coupling Promotes Iron-Catalyzed Electrochemical CO2 Reduction at Low Overpotentials

Biological and heterogeneous catalysts for the electrochemical CO2 reduction reaction (CO2RR) often exhibit a high degree of electronic delocalization that serves to minimize overpotential and maximize selectivity over the hydrogen evolution reaction (HER). Here, we report a molecular iron(II) system that captures this design concept in a homogeneous setting through the use of a redox non-innocent terpyridine-based pentapyridine ligand (tpyPY2Me). As a result of strong metal-ligand exchange coupling between the Fe(II) center and ligand, [Fe(tpyPY2Me)](2+) exhibits redox behavior at potentials 640 mV more positive than the isostructural [Zn(tpyPY2Me)](2+) analog containing the redoxinactive Zn(II) ion. This shift in redox potential is attributed to the requirement for both an open-shell metal ion and a redox noninnocent ligand. The metal-ligand cooperativity in [Fe(tpyPY2Me)](2+ )drives the electrochemical reduction of CO2 to CO at low overpotentials with high selectivity for CO2RR (>90%) and turnover frequencies of 100 000 s(-1) with no degradation over 20 h. The decrease in the thermodynamic barrier engendered by this coupling also enables homogeneous CO2 reduction catalysis in water without compromising selectivity or rates. Synthesis of the two-electron reduction product, [Fe(tpyPY2Me)](0) (,) and characterization by X-ray crystallography, Mossbauer spectroscopy, X-ray absorption spectroscopy (XAS), variable temperature NMR, and density functional theory (DFT) calculations, support assignment of an open-shell singlet electronic structure that maintains a formal Fe(II) oxidation state with a doubly reduced ligand system. This work provides a starting point for the design of systems that exploit metal-ligand cooperativity for electrocatalysis where the electrochemical potential of redox non-innocent ligands can be tuned through secondary metal-dependent interactions.

Do you like my blog? If you like, you can also browse other articles about this kind. Thanks for taking the time to read the blog about 139-07-1, Recommanded Product: 139-07-1.

Reference:
Metal catalyst and ligand design,
,Ligand Template Strategies for Catalyst Encapsulation – NCBI

Chemistry, like all the natural sciences, begins with the direct observation of nature¡ª in this case, of matter.206996-60-3, Name is Cerium(III) acetate xhydrate, SMILES is CC(O[Ce](OC(C)=O)OC(C)=O)=O.[H]O[H], belongs to catalyst-ligand compound. In a document, author is Kumandin, Pavel A., introduce the new discover, Recommanded Product: 206996-60-3.

Influence of the N -> Ru Coordinate Bond Length on the Activity of New Types of Hoveyda Grubbs Olefin Metathesis Catalysts Containing a Six-Membered Chelate Ring Possessing a Ruthenium-Nitrogen Bond

An efficient approach to the synthesis of new types of Hoveyda-Grubbs catalysts containing an N -> Ru bond in a six-membered chelate ring is proposed. The synthesis of the organometallic compounds is based on the interaction of ready accessible 2-vinylbenzylamines and 1,3-bis(2,4,6-trimethylphenyl)2-trichloromethylimidazolidine ligands with dichloro(3-pheny-1H-inden-1-ylidene)bis(tricyclohexylphosphane)ruthenate, and it afforded the target ruthenium complexes in 70-80% yields. Areas of practical utility and potential applications of the obtained chelates were highlighted by tests of the catalysts in different olefin cross metathesis (CM) and ring-closing-metathesis (RCM) reactions. These experiments revealed a high catalytic performance (up to 10(-2) mol %) of all the synthesized structures in a broad temperature range. The structural peculiarities of the resultant ruthenium catalysts were thoroughly investigated by X-ray crystallography, which allowed making a reliable correlation between the structure of the metallo-complexes and their catalytic properties. It was proved that the bond length between ruthenium and nitrogen in the six-membered chelate ring has the greatest effect on the stability and efficiency of the catalyst. As a rule, the shorter and stronger the N -> Ru bond, the higher the stability of the complex and the worse its catalytic characteristics. In turn, the coordination N -> Ru bond length can be finely tuned and varied over a wide range of values by changing the steric volume of the cyclic substituents at the nitrogen atom, which will make it possible, as appropriate, to obtain in the future metal complexes with predictable stability and the required catalytic activity. Also, it was found that complexes in which the nitrogen atom is included in the morpholine or isoquinoline rings are the most efficient catalysts in this series. An attempt to establish a correlation between the N -> Ru bond length and the H-1 and C-13 chemical shifts in the Ru=CH fragment has been made.

The proportionality constant is the rate constant for the particular unimolecular reaction. the reaction rate is directly proportional to the concentration of the reactant. I hope my blog about 206996-60-3 is helpful to your research. Recommanded Product: 206996-60-3.

Reference:
Metal catalyst and ligand design,
,Ligand Template Strategies for Catalyst Encapsulation – NCBI

The reaction rate of a catalyzed reaction is faster than the reaction rate of the uncatalyzed reaction at the same temperature. Application In Synthesis of (4S,4S)-2,2-(Propane-2,2-diyl)bis(4-phenyl-4,5-dihydrooxazole), 131457-46-0, Name is (4S,4S)-2,2-(Propane-2,2-diyl)bis(4-phenyl-4,5-dihydrooxazole), SMILES is CC(C1=N[C@@H](C2=CC=CC=C2)CO1)(C3=N[C@@H](C4=CC=CC=C4)CO3)C, in an article , author is Das, Anish Kumar, once mentioned of 131457-46-0.

Defects Engineering on Ceria and C-C Coupling Reactions Using [Au-11(PPh3)(7)I-3] Nanocluster: A Combined Experimental and Theoretical Study

Ligand protected atom-precise gold-based catalysts have been utilized in many essential chemical processes, but their mechanism and the fate of the catalyst during reaction are still unrevealed. Atom-precise cluster without ligands are thus highly desirable to maximize atom efficiency, but making these in solution phase is challenging. In this scenario, catalysts with dispersion on oxide support are highly desirable to understand the role of metal core during catalytic reaction. Here, we report the synthesis of Au-11(PPh3)(7)I-3 cluster that consists of an incomplete icosahedron core. During its impregnation process on CeO2 support, all of the ligands were removed from the kernel and the Au-11 kernel fits into the defects of ceria (embedded onto the oxygen vacancy of ceria (111) plane). This Au-11@CeO2 has high atom efficiency and catalytic activity for Ullmann-type C-C homocoupling reactions for electron rich substrates. Density functional theory calculations showed that hexagonal arrangements of Au-11 kernel on (111) plane of CeO2 is the most stable one. Theoretical calculations also proved that the atop gold atom has more favorable interaction with phenyl iodide than the second layer gold atoms of the Au-11@CeO2. This demonstrated that the present catalyst mimics the single-atom catalyst-like behavior in facilitating the coupling reactions.

But sometimes, even after several years of basic chemistry education, it is not easy to form a clear picture on how they govern reactivity! 131457-46-0, you can contact me at any time and look forward to more communication. Application In Synthesis of (4S,4S)-2,2-(Propane-2,2-diyl)bis(4-phenyl-4,5-dihydrooxazole).

Reference:
Metal catalyst and ligand design,
,Ligand Template Strategies for Catalyst Encapsulation – NCBI

Application of 206996-60-3, As an important bridge between the micro and macro material world, chemistry is one of the main methods and means for humans to understand and transform the material world. 206996-60-3, Name is Cerium(III) acetate xhydrate, SMILES is CC(O[Ce](OC(C)=O)OC(C)=O)=O.[H]O[H], belongs to catalyst-ligand compound. In a article, author is Clausen, Christian M., introduce new discover of the category.

What Atomic Positions Determines Reactivity of a Surface? Long-Range, Directional Ligand Effects in Metallic Alloys

Ligand and strain effects can tune the adsorption energy of key reaction intermediates on a catalyst surface to speed up rate-limiting steps of the reaction. As novel fields like high-entropy alloys emerge, understanding these effects on the atomic structure level is paramount: What atoms near the binding site determine the reactivity of the alloy surface? By statistical analysis of 2000 density functional theory calculations and subsequent host/guest calculations, it is shown that three atomic positions in the third layer of an fcc(111) metallic structure fourth-nearest to the adsorption site display significantly increased influence on reactivity over any second or third nearest atomic positions. Subsequently observed in multiple facets and host metals, the effect cannot be explained simply through the d-band model or a valence configuration model but rather by favorable directions of interaction determined by lattice geometry and the valence difference between host and guest elements. These results advance the general understanding of how the electronic interaction of different elements affect adsorbate-surface interactions and will contribute to design principles for rational catalyst discovery of better, more stable and energy efficient catalysts to be employed in energy conversion, fuel cell technologies, and industrial processes.

Application of 206996-60-3, Because enzymes can increase reaction rates by enormous factors and tend to be very specific, typically producing only a single product in quantitative yield, they are the focus of active research.you can also check out more blogs about 206996-60-3.

Reference:
Metal catalyst and ligand design,
,Ligand Template Strategies for Catalyst Encapsulation – NCBI